Method of treating peaches



Dec. 30, 1958 R. D. GERWE ET AL 2,865,709

METHOD oF TREATING PEAcHEs Filed June 22, 1953 RAYMOND D. GERWE l Mmmm MARTIN A. sLAnE..1R.

E'I[3 z BY #M WWW ATTORNEY `METHOD OF TREAT-ING PEACHES poration, San Jose, Calif., a corporation of Delaware Application June 22, 1953, Serial No. 363,308

6 Claims. (Cl. 99-168) The present invention relates to the treatment of fruit to preserve its freshness. More particularly the present invention relates to methods, media, and apparatus for providing fruit with a coating of wax to'reduce loss of moisture, protect it from direct exposure to the atmosphere, and in this manner slow down its aging process.

Peaches are amongst the most perishable of all fruit, and it has long been recognized as highly desirable to provide them with a protective coatingl of wax yso as to preserve their freshness until such time when they are sold on the market. Unfortunately, however, peaches are also a most delicate type of fruit, and it has therefore been a problem to provide them with a wax coating with-y is the fact that the surface of peaches is fuzzy so that it isv diicultrfor any coating material to reach, and adhere to, the basic surface of the fruit. While it has been the practice to remove .the fuzz from the peaches by a method known as de-fuzzing which is accomplished by bringing the peaches into contact with rotating brushes, these defuzzing processes fail to remove all the fuzz and leave at least a multitude of. short stubbles on the peach skin. Theseistubbles and any residual fuzz make it ditiicult for the coating material to adhere to the peaches and to form a thin, continuous and all-enclosing film around the fruit.

It is an object of the present invention to provide a` coating preparation that lends itself readilyfor application to lsuch delicate fruit as peaches, without harmful effects thereon. Y

Another object is to provide a method of applying a coating preparation to peaches in such a manner that a thin, durable and continuous film is formed around the fruit irrespective of fuzz and/or stubbles on its surface.

'Another object is to provide peaches with a thin, durable, and water repellent protective coating that will not smother the fruit, yet make it possible to expose it safely to cold water baths, such its temperature.

`Another object is toprovide a simple and effective apparatus for treating peaches in such a manner that a thin protective coating of a wax or wax-like substance is formed around the fruit.

- We have found that preparations comprising a wax or wax-like substance dissolved in, a rened vegetable oil niayreadily be vapplied to peaches and result `in thin, con-r tinuous and durable wax lilms around the fruit without harmful effects upon the tender skin thereof. For this purpose any one of the following waxes, or wax-like sub- Similarly, it proved unsatisas may be employed to lower l United States Patent O 2,866,709 Patented Dec. 30, 1958 Parafn wax Spermaceti Y l v Partially hydrogenated soyabean oil-Modifat 134-A Fractionally distilled fatty acids of cocoanut oil-Alifat Myristic acid-Neo-fat 13 Sorbitan monostearate-Span 60 Polyoxyethylene sorbitan monostearate-Tween 61 Glyceryl monomyristate Cetyl alcohol Coco-butter These waxes or wax-like substances may be dissolved in any one of the following vegetable oils: Cottonseed oil, corn oil, olive oil, peanut oil, soya bean oil, sesame oil, and the like.

As a practical example, a preparation made from rened cottonseed oil and containing from .25 to 5.0% by weight of refined paraiiin wax proved `highly satisfactory. It proved beneficial to add from .1% to .2% by weight of an anti-oxidant such' as nordihydroguaiaretic acid commonly known as N. D. G. A., Alcolec S, a derivative of lecithin, or Stabolec B, a compound of lecithin, citric acid, and propyl gallate, to the treating solutions. The usefulness of the preparations as treating agents for the preservation of peaches may be increased by the addition of small quantities of a suitable oil-soluble fungicide, such as orthophenylphenol, salicyl anilide, or the organic amine salt of the latter;

To cause the formation of a thin, continuous and durable iilm around the fruit, the preparation of the invention should be applied in highly atomized form and at a high velocity. This may be accomplished by means of pneumatic spray nozzles. When applied in this manner, it will form an extremely thin yet durable protective iilm around the fruit in spite of fuzz or stubbles that may be present on its surface. The results are particularly satisfactorywhen the fruit is brushed with horsehair brushes as the atomized spray of the preparation is applied n thereto.

Fig. 2 is an axial section through one of the pneumatic I spray nozzles employed in the apparatus illustrated in Fig. 1.

In Fig. l the reference numeral 10 designates a sequence of eight horizontally disposed cylindrical horsehair brushes 12 that are adjacently positioned in the manner of a roller conveyor and which are mounted upon' an equal number of parallel spindles 14 that extend transversely across and are rotatably mounted in the side Walls 16 of an enclosure 18. One end wall 19 of said enclosure is provided with a feed opening 2G to receive an inclined feed chute 22 through which the fruit is delivered onto the horsehair brushes 12. The inner end of the chute 22 is hinged to a shelf 24 that is secured to the inner face of the endwall 19 and the outer end of the chute is yieldably maintained in a raised position by a suitable spring `means 30 that bears again'st another shelf 32 which is provided in the opposite end Wall 27 thereof, the brushes .12 are rotated in counterclockwise direction as viewed 1n Fig. 1. This may be accomplished by means of an endless sprocket chain 34 that is driven from a sprocket 36 which is mounted upon the drive shaft 38 of an elec;

tric motor 40 and which is trained yover an idlerrsprocket 42 and sprockets 44 that are mounted upon the spindies 14 adjacent the outer surface of one of the side walls N16 of` the enclosure. Themotor `40 may Abebolted to a base panel 46 disposed belowuthe enclosure ,i 18 and supported from the legs 48 thereof. In order that the fruit delivered onto the rotary brushes 12 may not be come lodged in the interstces between adjacent brushes, rubber-sheathed dragging bars 50 are `drawn over the path established by the upper segments of the rotary brushes during operation of the machine. At their opposite ends said bars 50 are pivotally secured to arms 52 that depend` from a pair of endless sprocket chains 54 which are trained about pairs of sprockets 56 `and 58, respectively. Said sprocket pairs are firmly mounted upon a transverse shaft 60 and stub shafts 62, respectively, located near the discharge and feed ends of the enclosure 18 and rotatablysupported in the side-walls 16 thereof. VThe shaft 60 atthe discharge end of thel enclosure is driven from the hereinbefore'mentioned motor 40 by means of an endless sprocket chain 64 that is trainedaround a, sprocket\65 mounted upon the spindle 14 of the last of the rotary brushes 12 ,and an idler sprocket 66 rotatably supported from the side wall 16 above the level of shaft 60. Said sprocket chain 64 engages with its outer periphery a sprocket 69 that is `firmly secured to the shaft 60.

. Mounted in the ceiling 70,of the enclosure 18 near the feed end thereof are several pneumatic spray noz-` zles 72, only one being visible in Fig. l. Said nozzles are arranged to direct their spray cones against the fruit as it moves from thefeed chute 22 onto the conveyor path formed by thehorsehair brushes 12. A pneumatic spray houle of the type adapted to produce a spray of sucient velocity and atomization to form a thin yet continuous and durable wax film around the fruit is illustrated by way`iof example in Fig. l2; A pump 74 delivers the treating preparation from `a supply tank (not shown) through a conduit 76 to an inlet port 77 of saidnozzle. During operation of theapparatus the pump is continuously driven from the hereinbefore mentioned electric motor 40 by means of a transmission 80 comprising a sprocket 82, an endless sprocket chainv 84, a sprocket'86 mounted upon a `shaft'87, another sprocket 88 mounted upon said shaft 87, an endless sprocket chain 89, and a sprocket 90 that is rmly mounted upon the drive shaft 92` of the pump. Compressed ar is delivered to another entrance port 94 of the nozzle 72 through a conduit 96 from a compressor 98 thattis mounted upon the same base panel 46 as `the `motor 40.r Said compressor 98 is driven from the mo- 4 H In an exemplary embodiment ofthe invention, the pump 74 was arranged tondeliver the treating liquid to the nozzles 72 at a pressure of about 10 lbs. per square inch and the compressor was arranged to deliver air to the nozzles at a pressure of about l2 lbs. per square inch. The horsehair brushes had an overall diameter of 41/2 inches and a core diameter of 21/2 inches, and they were mounted with :their center axes spaced 5 inches apart and driven at a rotational speed of about 175 R. P. M. For optimum results, we found that the speed of rotation cfr-brushes of the defined size should not be less thanlOO R. P. M., otherwise they will not adequately spread the fcoating preparation around the fruit nor rub it sufficiently into the surface thereof.

On the other hand, speeds lin excess of 200 R. P. M. are

liable to injure the skin of the fruit.

To prevent waste of the treating preparation, the supply conduit 76 may comprise a normally closed valve 116 which is controlled by a solenoid 118, and the power circuit of the solenoid may contain a normally open switch 120 that is disposed below and is arranged to be closed by the feed chute 22, whenever said chute islowered on its hinge 28 against the urgency of the spring means 30 under the weight of fruit delivered thereonto. Closure of switch 120 energizes the solenoid 118 which opens the valve 116 so that treating preparation is delivered to the nozzle and is hurled against the fruit that closed the switch 120, as it reaches the rotary brushes 12. As soon as the supply of fruit to the chute 22 is nterrupted, however, the spring means 30 restores the chute to? its normally raised position permitting the switchV 120 to return to open condition.` As a result thereof, the solenoid 118 is de-energized and the valve 116 blocks the conduit 76 causing the liquid delivered into said conduitA under the force of pump 74 to return to the supply tank through a shunt line 122 controlled by a relief valve` 123.

In order to avoid that unused portions of the atomized spray within the enclosure 18 may reach, and contaminate, the atmosphere around the sprayingv apparatus, a fan `124 driven by an electric motor 126 may be mounted upon the roof 70 of the enclosure near the discharge endv A thereof to exhaust the atmosphere within said enclosure through a suitable funnel 127 that extends partially over tor 40 through a transmission 100 comprising the .here-I r inbefore `mentioned sprocket 82, the aforementioned sprocket chain 84, the hereinbefore mentioned sprocket 86 mounted uponshaft 87,` a large diameter sprocket 102 mounted upon said shaft 87, an endless sprocket chain 104, and a sprocket 106 mounted upon the drive shaft108 of the compressor 98.

The stream of treating liquid supplied to the nozzle 72 by the action of pump` 74 is forced through a narrow centrally located aperture 110 to form a primary spray cone, and the air introduced into said nozzle unf der the action of compressor 98 impinges along a conically converging surface 111 upon said primary spray` cone. The resultant mixture of treating liquid and air passes `then through another narrow aperture 112 and a slot 114 into the outside atmosphere forming a spray that ings the treating liquid in extremely fine dispersion and at high velocity against the 'fruit which passes underneath the nozzles 72 and which iscontinuously turned and twisted bythe rotating horsehair brushes so as to present all its sides to the film-forming sprays.` At the` same time contact, of the rotating horsehair brushes with the sprayed fruit rubs the `spray onto the basic fruitsuri face and spreads it evenly over the fruit.

, individual peaches ranges from only .l to .5 cubic centithe discharge opening 26. Said fan may be arranged to deliver the exhausted atmosphere into a chimney 130.

In carrying out the processes of the invention in practice, peaches are first de-fuzzed in the customarymanner by the `use of rotary brushes. livered intolthe described apparatus, with the rotational speed of the horsehair brushes 12 adjusted, withinmthe, previously stated limits, 'to pass the fruit through the` n enclosure 18 within a period of from l0 to 20 seconds. "When the fruit leaves the apparatus through the discharge,

opening 26, it is provided with a continuous, protective' film which is extremely thin as is demonstratedabyfthe,

fact that the amount of treating liquid applied to the il* meter.v The lms thus formed are completelyzihydroe;

phobie so that the fruit may, prior to shipping, besb-J:

jected to a cooling water bath wherein thewtemperature of the peaches is` reduced to approximately 45? Flwith-q n, out` harmful effect, and any condensation uponthe :fruit: which may form when it is transferred from a colder to a warmer atmosphere will in no way impair the fruit# As an added effect, the film of the invention reduces'loss of moisture due to evaporation and los's Aof natural sugars; such as result from high rates of respiration'of. the hara vested fruit. In consequence, peaches treatedinaccord-i ance with the invention remain iirm and retain `their fresh appearance long after `untreated peaches `have begunos lose weight and shrivel, and assume.'generallyl'anfagcdf appearance. In fact, the treatment o f theinvention ini tensifiesthe natural red, pink and yellow colors of theA i fruit and, therefore, increases its eyeV appeal over that. of

untreated fruit. Moreover, the films provided around They are then def that we do not wish to be limited to the constructionaldetails shown or the exemplary ingredients and percentages stated, which may be departed from without departing from the scope and spirit of the invention. It should also be understood that Wherever the appended claims call for a wax, this term is meant to include not only a true Wax but also wax-like substances of the type mentioned in the hereinbefore given list.

Having described our invention, what we claim is:

l. The method of treating fresh peaches by providing them with a lilm for preserving their freshness, which comprises subjecting the fruit to a highly atomized spray of a wax dissolved in a refined vegetable oil, the concentration of said wax in said vegetable oil being from .25% to 5% by weight.

2. The method of treating fresh peaches by providing them with a lm for preserving their freshness, which comprises subjecting the fruit to a highly atomized spray of a wax dissolved in a refined vegetable oil while brushing its surface with a horsehair brush, the concentration of said wax in said vegetable o-il being from .25% to 5% by weight.

3. The method of treating fresh peaches for preserving their freshness, which comprises subjecting the fruit to an atomized spray of wax dissolved in a refined vegetable oil while brushing it with a rotating horsehair brush to form a thin coating of the wax around the fruit, the concentration of said wax in'said vegetable oil being from .25% to 5% by weight, and thereafter subjecting the fruit to refrigerated water.

4. The method of treating fresh peaches for preserving their freshness, which comprises de-fuzzing the fruit and thereafter subjecting the fruit to an atomized spray of wax dissolved in a refined vegetable oil Whilefbrushing it with a rotating horsehair brush to form a thin coating of wax around the fruit, the concentration of said wax in said vegetable oil being from .25% to 5% by weight.

5. The method of treating fresh peaches for preserving their freshness which comprises de-fuzzing the fruit, thereafter subjecting the fruit to an atomized spray of wax dissolved in a refined vegetable oil while brushing it with a rotating horsehair brush to form a thin coating of said wax around the fruit, the concentration of said wax in said vegetable oil being from .25% to 5% by weight, and thereafter subjecting the fruit to refrigerated water until its temperature has dropped to about F.

6. A method of treating a peach having particles of fuzz on its outer surface, which comprises directing an atomized liquid spray of wax dissolved in a rened vegetable oil toward the peach at a high velocity to cause said spray to pass between the particles of fuzz on the peach and to impinge on and adhere to the surface of the peach as a thin coating, said liquid spray comprising a rened vegetable oil containing from .25% to 5.0% by weight of wax.

References Cited in the file of this patent UNITED STATES PATENTS 

1. THE METHOD OF TREATING FRESH PEACHES BY PROVIDING THEM WITH A FILM FOR PRESERVING THEIR FRESHNESS, WHICH COMPRISES SUBJECTING THE FRUIT TO A HIGHLY ATOMIZED SPRAY OF A WAX DISSOLVED IN A REFINED VEGETABLE OIL, THE CONCENTRATION OF SAID WAX IN SAID VEGETABLE OIL BEING FROM .25% TO 5% BY WEIGHT. 